Mine only has 125 hours so i just left in insides alone. Next winter I should have close to 300hrs. then i want to refresh with roller cams and some head work. I'm going to call Mark at Precision and see if he has a tune for my setup.

2" is just enough room for whipple Low Pro intercoolers. I also have a way to plumb them without have to add thru hull pickups and not starving the motor of any of its cooling.

When I do the refresh I might add intercoolers at that time. How did you plumb yours?

I Tee'd off the water pump inlet hose and added a check valve just off the tee. The check valve opens when hose pressurizes (at about 40mph) force feeding the cooler. Also I Tee'd off the pump outlet hose and installed a pressure relief valve, which Tee's into the intercoolers feed line downstream from the check valve. This feeds the innercooler right when you put the sticks forward and pump pressure builds. It will take some of the engines cooling water at lower speeds then the inlet check valve opens at high speed when the motor needs all the pumps cooling capacity.

This is my 4th rendition of plumbing on the chiller. I fed it directly teed off the pump outlet hose...idled like a cold carbed motor with no choke and temp would climb on motor at high speed. I then added the pressure relief valve to in the feed line. This worked OK but I did not feel it supplied enough water to the cooler (and that was stolen from the motor). Not wanting to add a transom pickup, I teed off the water pump inlet hose and added a check valve in the chillers feed line. This worked good at higher speeds when it opened but opened a little too late for my liking. When the water started flowing it was pretty damn hot! So with a little thought I have a combination of pump feed for low speed and force feed for high speed.

BTW...I have a imco lower with very large intake slot so I can not speak for how it would work on a merc lower.

Without chillers your pistons will get hot in a hurry. Better safe. I think the stock pistons are set up for 4-6 psi boost if I am not mistaken. Heat could get high w those large blowers. I'm sure you are all over this , but just be carefull !!


Chad

I'd bet that 8-71 is making less heat at 6 psi than his stock 256's made at 4.5 psi

I have thought about switching to a no chiller 8-71 setup myself, to save the hassle of the chiller plumbing and issues

Mine feed off the stock waterpump the entire time.I have sepaeratre dumps out the side and run about 10 psi water at w o t. The merc fuel injection seems to have all the ideling gremlins covered.I can send you a pic when you are ready. But I do like Jrider's check valve set up. Hope this helps

ahh.. Lean something new every day. If I had no chillers I would have not have to have scoops in my sun deck Leads me to think. Next refresh . Better rods.. JE pistons.... New blowers with the chillers.. Maybe I could be running 850's.. But then I'd need new drives .. lol

From what I've learned from Dyers the 8-71's are more efficient and will produce less heat running at 5% over than the 256's. At 5% over it 5-6 pounds of boost. Waiting on Fedex to get here with the lower pullies so i can fire this up. Funny thing my wife was asking question about the Blowers and I was telling here that these would whin more than the old ones. She said she like the wining sound and was wonder would go faster.......

The 575 already has crower H-beam rods, crower crank and JE pistons stock. Although you will make even less heat if you change the pistons and raise the compression to 8.75:1 and turn the boost down. The flat tappet cam is the thing that needs the upgrade in a 575.